<html><head></head><body><div class="ydpe3aeeb52yahoo-style-wrap" style="font-family:Helvetica Neue, Helvetica, Arial, sans-serif;font-size:16px;"><div><div dir="ltr" data-setdir="false">><span><span style="font-size:11.0pt;color:#1F497D;">A good one using multi-phase zero-crossing switching will show none of that.</span></span></div><div dir="ltr" data-setdir="false"><br></div><div dir="ltr" data-setdir="false">I hadn't heard of multi-phase switchers before, so I googled it and found htis nice doc I figured might interest people:<br></div><div dir="ltr" data-setdir="false"><a href="https://www.ti.com/lit/an/slva882b/slva882b.pdf" rel="nofollow" target="_blank">https://www.ti.com/lit/an/slva882b/slva882b.pdf</a></div><div><br></div><div dir="ltr" data-setdir="false">the only problem is that it doesn't reference the zero-crossing part... I'm having less luck finding that... have you got any good references for that?</div><div dir="ltr" data-setdir="false"><br></div><div dir="ltr" data-setdir="false">thank you!</div><div dir="ltr" data-setdir="false"><br></div><div dir="ltr" data-setdir="false"><br></div><div><br></div><div class="ydpe3aeeb52signature"><div dir="ltr" style="font-family:Helvetica, Arial, sans-serif;font-size:16px;">Noah Vawter's futuristic electronic music instrument lab: <a href="https://youtube.com/diydsp" rel="nofollow" target="_blank">youtube.com/diydsp</a></div></div></div>
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On Tuesday, August 2, 2022 at 12:05:07 PM EDT, Mike Bryant <mbryant@futurehorizons.com> wrote:
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<p class="yiv4658734117MsoNormal"><span style="font-size:11.0pt;color:#1F497D;">I’ve been using SMPS in pro-audio equipment we design since the 1970s, as have most of the other top audio designers I know. Some took until the late 90s to
come round but from then on everybody who mattered accepted SMPS were better.
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<p class="yiv4658734117MsoNormal"><span style="font-size:11.0pt;color:#1F497D;"> </span></p>
<p class="yiv4658734117MsoNormal"><span style="font-size:11.0pt;color:#1F497D;">High frequency current spikes indicate a badly designed SMPS, nothing more. A good one using multi-phase zero-crossing switching will show none of that.</span></p>
<p class="yiv4658734117MsoNormal"><span style="font-size:11.0pt;color:#1F497D;"> </span></p>
<p class="yiv4658734117MsoNormal"><span style="font-size:11.0pt;color:#1F497D;">Have a look inside every pro-audio product nowadays and you’ll find a SMPS. And to be sold they have to pass mains radiated tests so there is very little mains-side
noise. Indeed it is linear supplies which often used to fail those tests as they distorted the mains signal more due to core hysteresis.</span></p>
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<p class="yiv4658734117MsoNormal"><span style="font-size:11.0pt;color:#1F497D;">So I will submit that you have a somewhat jaundiced view.</span></p>
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<p class="yiv4658734117MsoNormal"><span style="font-size:11.0pt;color:#1F497D;"> </span></p>
<div id="yiv4658734117yqt19032" class="yiv4658734117yqt4552307985"><p class="yiv4658734117MsoNormal"><b><span style="font-size:10.0pt;" lang="EN-US">From:</span></b><span style="font-size:10.0pt;" lang="EN-US"> Synth-diy [mailto:synth-diy-bounces@synth-diy.org]
<b>On Behalf Of </b>Josh Nursing via Synth-diy<br clear="none">
<b>Sent:</b> 02 August 2022 16:47<br clear="none">
<b>To:</b> synth-diy@synth-diy.org<br clear="none">
<b>Subject:</b> Re: [sdiy] Help with Jupiter 8 clone</span></p>
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<p class="yiv4658734117MsoNormal">SMPS are the most polluting/noisy PSUs for audio purposes. Lots of high-frequency current spikes affect both downstream circuits and the mains they're connected to.</p>
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<p class="yiv4658734117MsoNormal">And before you start telling me about filtering the output of them, that does absolutely nothing for the mains-side noise.</p>
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<p class="yiv4658734117MsoNormal">Effects on audio are across the board - all audio frequencies suffer, and it's probably more noticeable in loss of bass frequencies.</p>
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<p class="yiv4658734117MsoNormal">On Tue, Aug 2, 2022 at 11:41 AM Mike Bryant <<a rel="nofollow noopener noreferrer" shape="rect" ymailto="mailto:mbryant@futurehorizons.com" target="_blank" href="mailto:mbryant@futurehorizons.com">mbryant@futurehorizons.com</a>> wrote:</p>
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<p style="" class="yiv4658734117MsoNormal"><span style="font-size:11.0pt;color:#1F497D;">How can audio suffer from putting a PSU in with 100 times better performance ? No 50/100Hz at
all and general noise almost zero. And it’s far less heat so everything else runs cooler and better. I think too many people see the noise from their phone charger or whatever and assume a proper SMPS is like that.</span></p>
<p style="" class="yiv4658734117MsoNormal"><span style="font-size:11.0pt;color:#1F497D;"> </span></p>
<p style="" class="yiv4658734117MsoNormal"><span style="font-size:11.0pt;color:#1F497D;"> </span></p>
<p style="" class="yiv4658734117MsoNormal"><b><span style="font-size:10.0pt;" lang="EN-US">From:</span></b><span style="font-size:10.0pt;" lang="EN-US"> Synth-diy
[mailto:<a rel="nofollow noopener noreferrer" shape="rect" ymailto="mailto:synth-diy-bounces@synth-diy.org" target="_blank" href="mailto:synth-diy-bounces@synth-diy.org">synth-diy-bounces@synth-diy.org</a>]
<b>On Behalf Of </b>Josh Nursing via Synth-diy<br clear="none">
<b>Sent:</b> 02 August 2022 16:35<br clear="none">
<b>To:</b> Synth DIY<br clear="none">
<b>Subject:</b> Re: [sdiy] Help with Jupiter 8 clone</span></p>
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<p style="" class="yiv4658734117MsoNormal">I really don't like the idea of replacing the linear PSU in those vintage synths with a SMPS one. Audio suffers.</p>
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<p style="" class="yiv4658734117MsoNormal">On Tue, Aug 2, 2022 at 7:45 AM Adam (synthDIY) <<a rel="nofollow noopener noreferrer" shape="rect" ymailto="mailto:synthdiy@adambaby.com" target="_blank" href="mailto:synthdiy@adambaby.com">synthdiy@adambaby.com</a>> wrote:</p>
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<p style="" class="yiv4658734117MsoNormal">Luís, I assume you’re aware of this</p>
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<p style="" class="yiv4658734117MsoNormal"><a rel="nofollow noopener noreferrer" shape="rect" target="_blank" href="https://synthronics.de/roland-jupiter-8-new-psu/">https://synthronics.de/roland-jupiter-8-new-psu/</a></p>
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<p style="" class="yiv4658734117MsoNormal">and this guy, who has been ominously quiet of late</p>
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<p style="" class="yiv4658734117MsoNormal"><a rel="nofollow noopener noreferrer" shape="rect" target="_blank" href="https://jup8restoration.wordpress.com/2019/10/22/new-power-supply-being-manufactured-for-a-jupiter-8/">https://jup8restoration.wordpress.com/2019/10/22/new-power-supply-being-manufactured-for-a-jupiter-8/</a></p>
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<p style="" class="yiv4658734117MsoNormal">A</p>
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<p style="" class="yiv4658734117MsoNormal">On 2 Aug 2022, at 3:57 am, Luís Marka via Synth-diy <<a rel="nofollow noopener noreferrer" shape="rect" ymailto="mailto:synth-diy@synth-diy.org" target="_blank" href="mailto:synth-diy@synth-diy.org">synth-diy@synth-diy.org</a>> wrote:</p>
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<p style="" class="yiv4658734117MsoNormal">Hi guys,<br clear="none">
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I am giving a serious thought about building a Jupiter 8 clone, and started to take a deeper look at the schematics (actually I already ordered some of the parts, so it looks like I will get it done eventually). In the PSU there are three GP-30G diodes tied
at the -15, +15 and +5V outputs, listed as "Hi-Fi Special" both in the schematics and in the parts list. I never heard anything about a "hi-fi special" diode, any idea what that means??<br clear="none">
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Cheers!<br clear="none">
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